Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Genes (Basel) ; 15(2)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38397145

RESUMO

Rehmannia glutinosa, a member of the Scrophulariaceae family, has been widely used in traditional Chinese medicine since ancient times. The main bioactive component of R. glutinosa is catalpol. However, the biogenesis of catalpol, especially its downstream pathway, remains unclear. To identify candidate genes involved in the biosynthesis of catalpol, transcriptomes were constructed from R. glutinosa using the young leaves of three cultivars, Beijing No. 3, Huaifeng, and Jin No. 9, as well as the tuberous roots and adventitious roots of the Jin No. 9 cultivar. As a result, 71,142 unigenes with functional annotations were generated. A comparative analysis of the R. glutinosa transcriptomes identified over 200 unigenes of 13 enzymes potentially involved in the downstream steps of catalpol formation, including 9 genes encoding UGTs, 13 for aldehyde dehydrogenases, 70 for oxidoreductases, 44 for CYP450s, 22 for dehydratases, 30 for decarboxylases, 19 for hydroxylases, and 10 for epoxidases. Moreover, two novel genes encoding geraniol synthase (RgGES), which is the first committed enzyme in catalpol production, were cloned from R. glutinosa. The purified recombinant proteins of RgGESs effectively converted GPP to geraniol. This study is the first to discover putative genes coding the tailoring enzymes mentioned above in catalpol biosynthesis, and functionally characterize the enzyme-coding gene in this pathway in R. glutinosa. The results enrich genetic resources for engineering the biosynthetic pathway of catalpol and iridoids.


Assuntos
Monoterpenos Acíclicos , Glucosídeos Iridoides , Plantas Medicinais , Rehmannia , Plantas Medicinais/genética , Rehmannia/genética , Rehmannia/metabolismo , Perfilação da Expressão Gênica
2.
Molecules ; 29(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276572

RESUMO

Selective supported catalysts have emerged as a promising approach to enhance carrier separation, particularly in the realm of photocatalytic hydrogen production. Herein, a pioneering exploration involves the loading of PdS and Pt catalyst onto g-C3N4 nanosheets to construct g-C3N4@PdS@Pt nanocomposites. The photocatalytic activity of nanocomposites was evaluated under visible light and full spectrum irradiation. The results show that g-C3N4@PdS@Pt nanocomposites exhibit excellent properties. Under visible light irradiation, these nanocomposites exhibit a remarkable production rate of 1289 µmol·g-1·h-1, marking a staggering 60-fold increase compared to g-C3N4@Pt (20.9 µmol·g-1·h-1). Furthermore, when subjected to full spectrum irradiation, the hydrogen production efficiency of g-C3N4@PdS@Pt-3 nanocomposites reaches an impressive 11,438 µmol·g-1·h-1, representing an eightfold enhancement compared to g-C3N4@Pt (1452 µmol·g-1·h-1) under identical conditions. Detailed investigations into the microstructure and optical properties of g-C3N4@PdS catalysts were conducted, shedding light on the mechanisms governing photocatalytic hydrogen production. This study offers valuable insights into the potential of these nanocomposites and their pivotal role in advancing photocatalysis.

3.
Molecules ; 28(23)2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38067575

RESUMO

Ultra-thin two-dimensional materials are attracting widespread interest due to their excellent properties, and they are becoming ideal candidates for a variety of energy and environmental photocatalytic applications. Herein, CdS nanorods are successfully grown in situ between a monolayer of g-C3N4 using a chemical water bath method. Continuous ultrasound is introduced during the preparation process, which effectively prevents the accumulation of a g-C3N4 layer. The g-C3N4@CdS nanocomposite exhibits significantly enhanced photocatalytic activity for hydrogen production under visible-light irradiation, which is attributed to a well-matched band structure and an intimate van der Waals heterojunction interface. The mechanism of photocatalytic hydrogen production is discussed in detail. Moreover, our work can serve as a basis for the construction of other highly catalytically active two-dimensional heterostructures.

4.
Molecules ; 28(8)2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-37110776

RESUMO

The effects of variations in the heat treatment process of milk on its quality and flavor are inevitable. This study investigated the effect of direct steam injection and instantaneous ultra-high-temperature (DSI-IUHT, 143 °C, 1-2 s) sterilization on the physicochemical properties, whey protein denaturation (WPD) rate, and volatile compounds (VCs) of milk. The experiment compared raw milk as a control with high-temperature short-time (HTST, 75 °C 15 s and 85 °C 15 s) pasteurization and indirect ultra-high-temperature (IND-UHT, 143 °C, 3-4 s) sterilization. The results showed no significant differences (p > 0.05) in physical stability between milk samples with different heat treatments. The DSI-IUHT and IND-UHT milks presented smaller particle sizes (p < 0.05) and more concentrated distributions than the HTST milk. The apparent viscosity of the DSI-IUHT milk was significantly higher than the other samples (p < 0.05) and is consistent with the microrheological results. The WPD of DSI-IUHT milk was 27.52% lower than that of IND-UHT milk. Solid-phase microextraction (SPME) and solvent-assisted flavor evaporation (SAFE) were combined with the WPD rates to analyze the VCs, which were positively correlated with ketones, acids, and esters and negatively associated with alcohols, heterocycles, sulfur, and aldehydes. The DSI-IUHT samples exhibited a higher similarity to raw and HTST milk than the IND-UHT samples. In summary, DSI-IUHT was more successful in preserving the milk's quality due to its milder sterilization conditions compared to IND-UHT. This study provides excellent reference data for the application of DSI-IUHT treatment in milk processing.


Assuntos
Temperatura Alta , Leite , Animais , Leite/química , Vapor , Temperatura , Esterilização , Proteínas do Soro do Leite/análise
5.
Nanomaterials (Basel) ; 13(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37110956

RESUMO

Photocatalyst performance is often limited by the poor separation and rapid recombination of photoinduced charge carriers. A nanoheterojunction structure can facilitate the separation of charge carrier, increase their lifetime, and induce photocatalytic activity. In this study, CeO2@ZnO nanocomposites were produced by pyrolyzing Ce@Zn metal-organic frameworks prepared from cerium and zinc nitrate precursors. The effects of the Zn:Ce ratio on the microstructure, morphology, and optical properties of the nanocomposites were studied. In addition, the photocatalytic activity of the nanocomposites under light irradiation was assessed using rhodamine B as a model pollutant, and a mechanism for photodegradation was proposed. With the increase in the Zn:Ce ratio, the particle size decreased, and surface area increased. Furthermore, transmission electron microscopy and X-ray photoelectron spectroscopy analyses revealed the formation of a heterojunction interface, which enhanced photocarrier separation. The prepared photocatalysts show a higher photocatalytic activity than CeO2@ZnO nanocomposites previously reported in the literature. The proposed synthetic method is simple and may produce highly active photocatalysts for environmental remediation.

6.
Nanomaterials (Basel) ; 12(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36296854

RESUMO

The design and construct pn heterojunction to reduce the recombination rate of photogenerated electron-hole pairs can effectively improve photocatalytic activity. In this study, ZnO/NiO heterojunctions were fabricated by annealing a Zn/Ni metal organic framework precursor synthesized via coprecipitation. The effects of the precursor annealing temperature on the microstructure, morphology, and optical properties of the ZnO/NiO nanocomposites were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-vis absorption spectroscopy. The results showed that the nanocomposite was composed of hexagonal wurtzite ZnO and cubic NiO, with the former being the dominant phase. Large ZnO nanoparticles were attached to small NiO nanoparticles, and a pn heterojunction interface was formed. The photodegradation performance of the nanomaterials was evaluated by monitoring the degradation of RhB under irradiation by ultraviolet light. The ZnO/NiO nanocomposites exhibited excellent photocatalytic activity when the annealing temperature was 550 °C. The photodegradation mechanism was also analyzed in detail, revealing that the heterojunction between the n-type ZnO and the p-type NiO played an important role in impeding the recombination of photogenerated electron-hole pairs and improving the photocatalytic efficiency.

7.
Small ; 18(40): e2204155, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36050884

RESUMO

The coordination environment of Ru centers determines their catalytic performance, however, much less attention is focused on cluster-induced charge transfer in a Ru single-atom system. Herein, by density functional theory (DFT) calculations, a competitive coordination-pairing between Ru clusters (RuRu bond) and single-atoms (RuO bond) is revealed leading to the charge redistribution between Ru and O atoms in ZnFe2 O4 units which share more free electrons to participate in the hydrogen desorption process, optimizing the proton adsorption and hydrogen desorption. Thus, a clicking confinement strategy for building a competitive coordination-pairing between Ru clusters and single-atoms anchored on ZnFe2 Ox nanosheets over carbon via RuO ligand (Ru1, n -ZnFe2 Ox -C) is proposed. Benefiting from the optimized coordination effect and the electronic synergy between Ru clusters and single-atoms, such a catalyst demonstrates the excellent activity and excellent stability in alkaline and seawater media, which has exceptional hydrogen evolution reaction activity with overpotentials as low as 10.1 and 15.9 mV to reach the current density of 10 mA cm-2 in alkaline and seawater media, respectively, higher than that of commercial Pt/C catalysts as a benchmark. Furthermore, it owns remarkably outstanding mass activity, approximately 2 and 8 times higher than that of Pt catalysts in alkaline and seawater media, respectively.

8.
Biomed Res Int ; 2022: 3370499, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928920

RESUMO

Baseball itself is a new sport. In the process of training, teachers often use traditional training methods, which leads to unsatisfactory training results. High-intensity intermittent and intensive interval training can better improve the efficiency of athletes' oxidation and energy supply and ultimately play a positive role in improving athletes' performance. This paper takes the influence of high-intensity and intensive interval training on the special endurance of baseball players as the research object. A series of functional training programs are developed through adaptive training, testing, coordination training, and recovery training. Through the use of experimental means to understand the influence of high-intensity interval training and intensive interval training on the physical fitness of baseball players, the paper is aimed at providing ways and means to improve the physical fitness level of baseball players in the future. Based on the experimental test data, functional training is different from traditional training methods to make up for the lack of training research. It is to improve the competitive ability of our baseball players and promote the development of our baseball. It plays an active role in improving the specific endurance, speed, and intermittent endurance of baseball players.


Assuntos
Desempenho Atlético , Beisebol , Treinamento Intervalado de Alta Intensidade , Atletas , Humanos , Aptidão Física
9.
Biomed Res Int ; 2022: 4625719, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35774272

RESUMO

In the process of competition and training, tennis players often carry out explosive force and extreme centripetal and eccentric contraction, while the ligament and joint capsule on the shoulder joint are relatively weak, which also makes the joint often appear injury caused by overuse. It has been the direction of scientific research to help athletes recover their functions and return to the arena through effective rehabilitation training and prerehabilitation training. In this paper, the reliability and short-term effect of wearing dynamic and static shoulder joint brace after arthroscopic repair of rotator cuff injury were studied through a controlled trial of tennis exercise for the treatment of shoulder injury. The purpose of this study was to apply the dynamic and static shoulder joint brace to patients with rotator cuff injury and shorten the recovery time of shoulder joint function the operation. This paper also studies the therapeutic effect verification of patients with rotator cuff injury during rehabilitation period by wearing shoulder joint brace with dynamic and static combination. Through the comparison between the experimental group and the control group, it is verified that the effect of rehabilitation intervention is better than that of the control group, which shows that the use of dynamic and static shoulder joint brace can improve the range of motion of shoulder joint and patient satisfaction, and the effect increases with time. This study improves the shoulder strength of tennis players through functional training, demonstrates the value and significance of functional training for the development of tennis through experiments, and provides a reference for athletes to improve their physical fitness training. At the same time, the research content of this paper can also provide references and promotion for sports events.


Assuntos
Lesões do Manguito Rotador , Lesões do Ombro , Articulação do Ombro , Tênis , Humanos , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Manguito Rotador
10.
Biomed Res Int ; 2022: 7378953, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35832853

RESUMO

In the past, in the study of special sports quality of heavy antagonistic sports events, the study of strength quality training was emphasized. The transformation of athletes' strength quality to special strength was highlighted, and the special exercises which tended to be consistent with the characteristics of wrestling events were added. However, in competition and training, athletes' spine bears a heavy load. Long-term static contraction of lumbar muscles can lead to excessive local load and injury of lumbar muscles. In this paper, the test results of athletes' joints are analyzed, and the waist protection scheme for athletes' strength training is obtained. First of all, solve the problem of athletes' action mode and improve athletes' muscle endurance. All special sports quality evaluation can reach a good level. Then, enhance athletes' explosive power. Thus, all special sports quality evaluations can reach an excellent level. It is concluded that the waist and back are the key parts to support their participation in various sports, maintain body balance, and realize power transmission. Through the study, it is found that there are significant differences in the muscle strength indexes of the maximum strength of the waist and back of athletes of different levels, which fully proves the characteristics of the maximum strength of the waist and back. Through the test, we can understand the flexion and extension strength, range, speed, force, and flexion and extension ratio of athletes' joints and take timely optimization measures according to the test results to avoid sports injuries in training. It has a key guiding significance for the measurement, analysis, and evaluation of athletes' joint muscle strength, as well as rehabilitation training after injury and prevention of reinjury.


Assuntos
Treinamento de Força , Esportes , Atletas , Humanos , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento de Força/métodos , Esportes/fisiologia
11.
Nanomaterials (Basel) ; 12(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35407242

RESUMO

The degradation of pollutants in wastewater using abundant resources and renewable energy sources, such as light, is attractive from an environmental perspective. ZnO is a well-known photocatalytic material. Therefore, in this study, a hierarchical ZnO microsphere precursor was prepared using a hydrothermal method. The precursor was subsequently annealed at different temperatures, which enabled the production of a ZnO catalyst having a controllable morphology. Specifically, as the annealing temperature increased, the precursor crystallized into hexagonal wurtzite and the crystallinity also increased. The catalysts were tested for their photocatalytic activity for the degradation of dye molecules (methylene blue and rhodamine B), and the catalyst sample annealed at 400 °C showed the best photocatalytic activity. The origin of this activity was studied using electron paramagnetic resonance spectroscopy and transient photocurrent measurements, and the structure of the optimal catalyst was invested using electron microscopy measurements, which revealed that it was formed of two-dimensional nanosheets having smooth surfaces, forming a 2D cellular network. Thus, we have presented a promising photocatalyst for the mineralization of organic contaminants in wastewater.

12.
Comput Struct Biotechnol J ; 19: 3954-3963, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34377362

RESUMO

Rehmannia glutinosa is a potent medicinal plant with a significant importance in traditional Chinese medicine. Its root is enriched with various bioactive molecules mainly iridoids, possessing important pharmaceutical properties. However, the molecular biology and evolution of R. glutinosa have been largely unexplored. Here, we report a reference genome of R. glutinosa using Nanopore technology, Illumina and Hi-C sequencing. The assembly genome is 2.49 Gb long with a scaffold N50 length of 70 Mb and high heterozygosity (2%). Since R. glutinosa is an autotetraploid (4n = 56), the difference between each set of chromosomes is very small, and it is difficult to distinguish the two sets of chromosomes using Hi-C. Hence, only one set of the genome size was mounted to the chromosome level. Scaffolds covering 52.61% of the assembled genome were anchored on 14 pseudochromosomes. Over 67% of the genome consists of repetitive sequences dominated by Copia long terminal repeats and 48,475 protein-coding genes were predicted. Phylogenetic analysis corroborates the placement of R. glutinosa in the Orobanchaceae family. Our results indicated an independent and very recent whole genome duplication event that occurred 3.64 million year ago in the R. glutinosa lineage. Comparative genomics analysis demonstrated expansion of the UDP-dependent glycosyltransferases and terpene synthase gene families, known to be involved in terpenoid biosynthesis and diversification. Furthermore, the molecular biosynthetic pathway of iridoids has been clarified in this work. Collectively, the generated reference genome of R. glutinosa will facilitate discovery and development of important pharmacological compounds.

13.
3 Biotech ; 11(7): 327, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34194911

RESUMO

To study the molecular mechanism of the hyperaccumulator plant Phytolacca americana against cadmium (Cd) stress, the leaves of P. americana treated with 400 µM Cd for 0, 2, 12, and 24 h were harvested for comparative transcriptome analysis. In total, 110.07 Gb of clean data were obtained, and 63,957 unigenes were acquired after being assembled. Due to the lack of P. americana genome information, only 24,517 unigenes were annotated by public databases. After Cd treatment, 5054 differentially expressed genes (DEGs) were identified. KEGG pathway enrichment analysis of DEGs showed that genes involved in the flavonoid biosynthesis and antenna proteins of photosynthesis were significantly down-regulated, while genes related to the lignin biosynthesis pathway were remarkably up-regulated, indicating that P. americana could synthesize more lignin to cope with Cd stress. Moreover, genes related to heavy metal accumulation, sulfur metabolism and glutathione metabolism were also significantly up-regulated. The gene expression pattern of several key genes related to distinct metabolic pathways was verified by qRT-PCR. The results indicated that the immobilization of lignin in cell wall, chelation, vacuolar compartmentalization, as well as the increase of thiol compounds content may be the important mechanisms of Cd detoxification in hyperaccumulator plant P. americana. Accession numbers: the raw data of P. americana transcriptome presented in this study are openly available in NCBI SRA database, under the BioProject of PRJNA649785. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02865-x.

14.
PeerJ ; 8: e9683, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879793

RESUMO

Climate change has a global impact on the water cycle and its spatial patterns, and these impacts are more pronounced in eco-fragile regions. Arid regions are significantly affected by human activities like farming, and climate change, which influences lake water volumes, especially in different latitudes. This study integrates radar altimetry data from 2002 to 2018 with optical remote sensing images to analyze changes in the lake areas, levels, and volumes at different altitudes in Xinjiang, China. We analyzed changes in lake volumes in March, June, and October and studied their causes. The results showed large changes in the surface areas, levels, and volumes of lakes at different altitudes. During 2002-2010, the lakes in low- and medium-altitude areas were shrinking but lakes in high altitude areas were expanding. Monthly analysis revealed more diversified results: the lake water levels and volumes tended to decrease in March (-0.10 m/year, 37.55×108 m3) and increase in June (0.03 m/year, 3.48×108 m3) and October (0.04 m/year, 26.90×108 m3). The time series lake water volume data was reconstructed for 2011 to 2018 based on the empirical model and the total lake water volume showed a slightly increasing trend during this period (71.35×108 m3). We hypothesized that changes in lake water at high altitudes were influenced by temperature-induced glacial snow melt and lake water in low- to medium-altitude areas was most influenced by human activities like agricultural irrigation practices.

15.
Arch Med Res ; 51(3): 224-232, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32147288

RESUMO

BACKGROUND: Investigation into the anti-cancer activities of natural products and their derivatives represents an efficient approach to develop safe and effective chemotherapeutic agents for the treatment of colorectal cancer. Helveticoside is a biologically active component of the seed extract of Descurainia sophia. This compound has been reported to regulate the genes related to cell proliferation and apoptosis in lung cancer cells, however its anticancer activity has not been fully explored yet. METHODS: Cell viability was evaluated by MTT and Trypan blue exclusion assay; cell apoptosis was measured by flow cytometry; mitochondrial membrane potential was determined by using JC1-mitochondrial membrane potential assay kit; protein levels were determined by western blot assay; in vivo tumor growth was assessed in a xenograft nude mice model. RESULTS: The current study demonstrated the in vitro anti-cancer activity of helveticoside against colorectal cancer using colorectal cancer cells SW480 and HCT116. Moreover, induction of apoptosis was found to mediate the cytotoxic action of helveticoside on SW480 and HCT116 cells. Based on the decrease in the mitochondrial membrane potential, upregulation of Bax, downregulation of Bcl-2 and cleavage of caspase-3 and 9, apoptosis was induced by helveticoside via mitochondria-mediated intrinsic apoptotic signaling pathways in colorectal cancer cells. Besides, using p53-knockout SW480 cells, the cytotoxic action of helveticoside was found to be p53-dependent. More importantly, administration of helveticoside inhibited the growth of HCT116 cells derived-colorectal cancer xenograft in mice via activation of apoptosis. CONCLUSIONS: Helveticoside might be a potential candidate for the development of novel chemotherapeutic agents for the treatment of colorectal cancer, while the potential toxic effects of helveticoside may be worthy of further investigations.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Glicosídeos Digitálicos/farmacologia , Estrofantinas/farmacologia , Animais , Antineoplásicos/efeitos adversos , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/patologia , Glicosídeos Digitálicos/efeitos adversos , Células HCT116 , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Nus , Camundongos SCID , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Estrofantinas/efeitos adversos , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína X Associada a bcl-2/metabolismo
16.
PeerJ ; 8: e8243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31915574

RESUMO

Estimating water requirements and water balance for irrigated agricultural areas are important and will facilitate the efficient allocation of water resources for agriculture while minimizing the impact on natural ecosystems in arid regions. Based on the Penman-Monteith formula and GIS technology, the irrigation water requirements (IWR) of three main crops (cotton, corn and wheat) during the growing season were estimated and their spatio-temporal changes over the past 23 years (1995-2017) were analyzed in Xinjiang province, China. Our results indicated a dramatic increase in IWR from 14.12 billion m3 in 1995 to 38.99 billion m3 in 2017 due to the rapid cropland expansion of approximately 2.58 × 104 km2 in this period. Monthly IWR usually peaked in summer from May to July and varied in different basins. From the perspective of crops, cotton was identified to have consumed the largest amount of water, reaching 26.39 billion m3 in 2017, accounting for 67.68% of total water consumption. Spatially, the fastest increasing rate of IWR was Tarim Basin, which was attributable to the increase in water requirement of cotton. By comparing IWR and actual irrigation of Xinjiang in 2014, the amount of water scarcity had reached -15.01 billion m3 (-9.80 billion m3 in Tarim Basin and -6.58 billion m3 in Junggar Basin). The planting areas of three main crops (wheat, corn and cotton) were more sensitive to IWR than rising temperature indicated by our model. This study is of great significance for the scientific allocation of water resources in the irrigated areas of the different prefectures of Xinjiang.

17.
Analyst ; 145(3): 858-864, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31845653

RESUMO

A novel electrochemical biosensor was reported for the first time to achieve highly sensitive DNA detection based on photoinduced atom transfer radical polymerization (photoATRP). In this work, PNA was applied as the capture probe to specifically recognize the target DNA (TDNA), and we utilized lung cancer DNA as TDNA. The ATRP initiator was introduced to the electrode surface via phosphate-Zr4+-carboxylate chemistry. PhotoATRP was activated under blue light irradiation based on a photoinitiator I2959, which produced free radicals via homolytic cleavage. Subsequently, Cu2+ was reduced to Cu+ with the assistance of the free radicals, and numerous electroactive probes were grafted onto the electrode surface. Under optimal conditions, the limit of detection (LOD) of this method was 3.16 fM (S/N = 3, R2 = 0.992), and the linear range was from 10 fM to 1.0 nM. More importantly, the preparation process of this biosensor was simple and less laborious with a low background signal, suggesting good potential in practical applications.


Assuntos
Técnicas Biossensoriais/métodos , DNA/análise , DNA de Neoplasias/análise , Técnicas Eletroquímicas , Eletrodos , Humanos , Luz , Limite de Detecção , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Polimerização
18.
Anal Sci ; 36(6): 681-685, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31839663

RESUMO

We propose a novel, ultrasensitive and low-cost sensor using reversible addition-fragmentation chain transfer (RAFT) polymerization as a signal amplification strategy for the detection of CYFRA 21-1 DNA fragment, a tumor marker of non-small cell lung carcinoma. The peptide nucleic acid (PNA) probes were firstly immobilized on magnetic beads (MBs) to capture the CYFRA 21-1 DNA specifically. After hybridization, CPAD was tethered to the hetero duplexes through carboxylate-Zr4+-phosphate chemistry. Subsequently, a number of fluorescent tags were introduced to the heteroduplexes through RAFT polymerization, leading to an amplification of the fluorescence signal. The sensor demonstrates a low limit of detection (LOD) of 0.02 fM. It has great selectivity with respect to base mismatch DNA, and high anti-interference ability in normal human serum. Overall findings of the study suggest that proposed sensor holds enormous potential to be used as a tool for the early-stage diagnosis of lung cancers.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Detecção Precoce de Câncer , Corantes Fluorescentes/química , Neoplasias Pulmonares/diagnóstico por imagem , Ácidos Nucleicos Peptídicos/química , Antígenos de Neoplasias/sangue , Biomarcadores Tumorais/sangue , DNA de Neoplasias/sangue , Corantes Fluorescentes/síntese química , Humanos , Queratina-19/sangue , Limite de Detecção , Estrutura Molecular , Hibridização de Ácido Nucleico , Ácidos Nucleicos Peptídicos/síntese química , Polimerização
19.
Biomed Pharmacother ; 115: 108878, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31060006

RESUMO

Pancreatic cancer is the fourth leading cause of cancer-related deaths worldwide. However, therapeutic strategies for the treatment of pancreatic cancer are still limited. Therefore, it is urgent for us to develop novel effective therapies for pancreatic cancer. In this study, we explored the effects of rosmarinic acid on pancreatic progression and explored the underlying molecular mechanisms. Rosmarinic acid significantly suppressed cell viability, cell growth, cell invasion and migration as well as epithelial mesenchymal transition (EMT) of pancreatic cancer cells, and induced cell apoptosis in pancreatic cells. In addition, rosmarinic acid significantly up-regulated the expression of miR-506 in pancreatic cancer cells, and knockdown of miR-506 attenuated the suppressive effects of rosmarinic acid on cell growth, cell invasion and migration and EMT, and prevented the enhanced effects of rosmarinic acid on cell apoptosis in pancreatic cancer cells. Mechanistically, the luciferase reporter assay showed that miR-506 targeted the 3' untranslated region of matrix metalloproteinase (MMP)-2/16, and miR-506 overexpression and rosmarinic acid treatment suppressed the expression of MMP2/16 in pancreatic cancer cells. Overexpression of MMP2/16 attenuated the inhibitory effects of rosmarinic acid on pancreatic cell invasion and migration. In vivo studies showed that rosmarinic acid dose-dependently suppressed tumor growth of pancreatic cancer cells, and increased the expression of miR-506, while suppressed the expression of MMP2/16 and Ki-67 in dissected tumor tissues from xenograft nude mice. Collectively, our results for the first time revealed the anti-tumor effects of rosmarinic acid in pancreatic cancer, and the anti-tumor effects of rosmarinic acid were via regulating the miR-506/MMP2/16 axis in pancreatic cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , Cinamatos/farmacologia , Depsídeos/farmacologia , Metaloproteinase 16 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , MicroRNAs/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Movimento Celular , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Metaloproteinase 16 da Matriz/genética , Metaloproteinase 2 da Matriz/genética , Camundongos , Camundongos Nus , MicroRNAs/genética , Invasividade Neoplásica , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Pancreáticas/genética , Regulação para Cima
20.
RSC Adv ; 9(4): 2277-2283, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35516105

RESUMO

The influence of the headgroup on the dynamics of three different alkylammonium cations confined in graphite oxide (GO) was studied by temperature-dependent impedance spectroscopy. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, thermogravimetry and elemental analysis served to characterize the composites. The alkylammonium cations were connected to the C-O- group of GO via ionic interactions, and the backbone of the confined molecule was distributed as a flat monolayer with the long axis parallel to the GO layer. Ngai's correlated-state model was used, with asymmetry at low temperature in the loss peaks. The calculated true activation energy of 114 meV ± 6% meV is almost the same as the internal rotation barrier of the alkyl macromolecule. We conclude that the relaxation process is definitely attributed to the wobbling around the long molecular axes of the confined ions, an intrinsic motion, not the reorientation of C-H at the headgroup, and it is also due to geometric structural symmetry at the headgroup of the alkylammonium molecules with the interaction of their backbones and the skeletons of GO resulting in the difference in the apparent activation energy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...